1 files changed, 51 insertions, 2 deletions
diff --git a/synapse/push/__init__.py b/synapse/push/__init__.py
index 5a437f9810..3d2e874838 100644
--- a/synapse/push/__init__.py
+++ b/synapse/push/__init__.py
@@ -13,7 +13,56 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import abc
+from typing import TYPE_CHECKING, Any, Dict, Optional
+
+from synapse.types import RoomStreamToken
+
+if TYPE_CHECKING:
+    from synapse.app.homeserver import HomeServer
+
+
+class Pusher(metaclass=abc.ABCMeta):
+    def __init__(self, hs: "HomeServer", pusherdict: Dict[str, Any]):
+        self.hs = hs
+        self.store = self.hs.get_datastore()
+        self.clock = self.hs.get_clock()
+
+        self.pusher_id = pusherdict["id"]
+        self.user_id = pusherdict["user_name"]
+        self.app_id = pusherdict["app_id"]
+        self.pushkey = pusherdict["pushkey"]
+
+        # This is the highest stream ordering we know it's safe to process.
+        # When new events arrive, we'll be given a window of new events: we
+        # should honour this rather than just looking for anything higher
+        # because of potential out-of-order event serialisation. This starts
+        # off as None though as we don't know any better.
+        self.max_stream_ordering = None  # type: Optional[int]
+
+    @abc.abstractmethod
+    def on_new_notifications(self, max_token: RoomStreamToken) -> None:
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def on_new_receipts(self, min_stream_id: int, max_stream_id: int) -> None:
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def on_started(self, have_notifs: bool) -> None:
+        """Called when this pusher has been started.
+
+        Args:
+            should_check_for_notifs: Whether we should immediately
+                check for push to send. Set to False only if it's known there
+                is nothing to send
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def on_stop(self) -> None:
+        raise NotImplementedError()
+
 
 class PusherConfigException(Exception):
-    def __init__(self, msg):
-        super().__init__(msg)
+    """An error occurred when creating a pusher."""